Make sure the kernel allows PROCCTL_REAP_ACQUIRE.
Make sure the kernel allows PROCCTL_REAP_ACQUIRE.

If the initial call fails, don't try to kill any child processes.
Also, always pkg_emit_errno() on any PROCCTL_REAP_KILL failure, not just for
errno==EINVAL.

khorben/pkg,junovitch/pkg,khorben/pkg,khorben/pkg,en90/pkg,junovitch/pkg,en90/pkg,skoef/pkg,skoef/pkg,Open343/pkg,Open343/pkg